i started when my girl was 6-7 mths old cos she wanted to grab hold of the spoon.
She's been holding on to the spoon during her meals ever since, but I still guide her cos I'm too lazy to wipe up the mess.
I think my girl's seen the adults eat, so she roughly knows how to use the spoon. Must get those spoons with big fat handles so that they are easier for bbs to hold. I like the ones from boon.